Towards a Characterization of Rational Expectations

R. J. Aumann and J. H. Drèze (2008) define a rational expectation of a player i in a game G as the expected payoff of some type of i in some belief system for G in which common knowledge of rationality and common priors obtain. Our goal is to characterize the set of rational expectations in terms of the game’s payoff matrix. We provide such a characterization for a specific class of strategic games, called semi-elementary, which includes Myerson’s “elementary” games.